FIELD OF THE INVENTION AND BRIEF DESCRIPTION OF THE PRIOR ART
The present invention relates to an arrangement for the non-destructive measurement of metal traces in the surface of material samples in which the sample surface is irradiated with X-ray radiation to provide flourescent radiation. A detector is positioned above the material sample to spectrometrically examine the flourescent radiation emanating from the material sample therein. Such X-ray radiation sweeps over the surface of the material sample from an adjustable X-ray source oriented toward the sample. The divergence of the exciting X-ray radiation is limited by means of two apertured members, these members being arranged at a quartz body serving as an optical bench. Such an arrangement is disclosed in DE-AS No. 2,911,596, which corresponds to U.S. Pat. No. 4,426,717, which is incorporated herein by reference.
Silicon wafers are the basis of highly integrated electronic components. Their purity must meet extreme requirements. These purity requirements are difficult to meet by production processes, particularly for the wafer surfaces, and therefore product monitoring is required. However, there is no measuring procedure in the prior art which permits on-line, non-destructive testing for impurities in such surfaces down to about 10.sup.11 atoms/cm.sup.2.
Although it is possible, with the above-mentioned prior art arrangement, utilize the effects occurring upon the total reflection of X-ray radiation to examine surfaces with sufficient sensitivity, this arrangement is suitable only for surfaces having a maximum diameter of about 50 mm. Moreover, with the prior art structural solution, contamination of the test object from contact with the metal components of the instruments is possible.